The touch panels have been utilized as inputs means for various electronic apparatuses. The touch panels can be classified into resistance type touch panel, capacitance type touch panel, ultrasonic type touch panel, and infrared type touch panel, etc., according to work principles. FIG. 1 shows a conventional infrared type touch panel for detecting a position of an object present in a particular region. The electronic apparatus 10 includes a display panel 20, multiple infrared receiving devices 30 and 32, and an infrared emitting device 40. The infrared receiving devices 30 and 32 and the infrared emitting device 40 are disposed on the perimeter of panel 20. When a finger or other object 60 is set in a certain position on the display panel 20, light emitted by the infrared emitting device 40 will be reflected by the object 60. Therefore, the infrared receiving devices 30 and 32 can sense light reflected by the object 60 from multiple angles. The infrared receiving devices 30 and 32 can translate the received light into electrical signals which are then transmitted to a processor 50. These electrical signals are correlated by the processor 50 to generate X and Y coordinates of the object 60. In short, the coordinates of the object 60 can be obtained by analyzing the light received by the infrared receiving devices 30 and 32. The processor 50 then sends these coordinates to an operating system to, for example, position a curser in the corresponding X and Y locations on the display panel 20.
However, although drawing directly on the display panel 20 with fingers or other objects 60 is possible, the finger or object 60 cannot communicate any other information to the operating system except for the X and Y coordinates. Therefore, many drawing attributes, such as line width, color, and rotation angle must be set though control buttons or other user interface, which requires users to interface with the electronic apparatus in an unnatural way. This limits the user's ability to interact with drawing programs in an artistic way and impedes the creative process.
Consequently, it is necessary to provide an input device capable of giving user the best control for communicating with the touch panel.